Rotary underreamer



April 7, 1925. 1,532,917

w. MEREDITH I ROTARY UNDERREAMER Filed April 14. 1924 SV A Patenteda'hpr.; 7. 12925.v

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SUUTH PASBENA, CALIFORNIA.

ROTARY UNDERREMER.

applicants mea apni it, 192i... serieu no. :loana To @ZZ whom t mayconcern Be it known that l, vWILLIAM MnRniorrn7 a citizen or the UnitedStates, and resident'of Huntington Beach, `in the county o of Grange.Stateof California, have invented new and useful Improvements in aRotary Underreamer, of which ythe following is a speciiication.

This invention relates to Aan underreamer 1o having cutters which may beexpanded into cutting position after the underreamer has been lowered*into the hole. v

The objects of this invention are iirst, to provide an underreamerhaving cutters, which are mounted to be moved into expanded position atthe will of the operator by rotation or the driil pipe; second, toprovide an underreamer of the character described which is selfcontained and requires no auxiliary control devices leading from the lvunderreainer to the surface of the ground 'for manipulation by theoperator; and third, to provide details of construction to insure easeof operation, simplicity, strength, and durability of structure.

rlhese objects together with other objects and correspondingaccomplishments are ob-y tained by means of the embodiment of myinvention iilustrated in the accompanying drawing, in which:

Fig. 1 an axial section partly in elevation showing Jthe underreamer incontracted position; 2 is an axial section of the underreamer inexpanded position; Fig. 3 is a fragmentary view partly in side elevationand partly in section as seen looking in the direction of the arrows 3 3of Fig. 1; Fig. 4 is a section as seen on the line 4-4 of Fig. 1, theview being on an enn larged scaie; Fig. is a section as seen on the iine5-5 of Fig. 1; Fie". 6 is a section as seen on 'the line of 1; and Fig.7 is a section as seen on the iine 7 3? of Fig. 1.

Referring more particularly to Fig. 1, the dot and dash lines indicatethe box of a tool joint disposed in a string of drill pipe. Theunderreamer has a body 8 Iprovided with a threaded pin at 'the up er endfor insertion in the boX'of-'the too joint.

The body has a cylindrical head flattened on opposite sides to rovide awrench hold 7F c body is `formed with as indicated by 9. .i

diainetrically opposite recesses 1G having their bottom walls convergingtoward. the bottom of the body forming ways undercut at the sides toreceive carriages in which the cutters are mounted." rihe owor end ofthe body is reduced in diameter and externally threaded as indicated by11. FX- tending axiaiiy of the body is a circulation passage 12. l

Mounted upon the ways on the body are carriages 11i. Mounted in thecarriages and extending longitudinally thereofare' pinties 15.`dournalled upon the pintles are rotary cutters 16. in 'the presentinstance, the cutters each consist of two rollers. A pair of spaced earsare provided at the iower end of each carriage las indicated 17 andjournalled therein by means off pins are arms 1.8. 'A block 19 ispivotally secured to the iower. end ozt arm 1"". Secured to the bottomof the body 8 and upon the threaded portion 11 is cage 2G. 'T is cagehas barrel upper portion, in the bore or which is mounted the block 19.The lower end 21 is :flattened the sides to provide wrench holds and isprovided with a threaded bore 22.

Swivelled the block 19 is a stem 23 having a fast thread. This stem isprovided with a circulation passage so positioned that the stem abutsthe lower end of the body, as shown in Fig. 2 a continuons passage isformed. Secur to the end oi" the stein 23 against rotation is a boa 2dfor a tapered pin 2.5 of the'tool joint type. The pin 25 is formed on afish taii bit 25.

lWhen the nnderreamer is lowered into the hole, it is in contractedposition shown in Fig. 1. When the tool has reached the place where itis desired to out, the drill stem is rotated in such a manner andstopped so as to cause the cage 20 to ride downwardly upon stem due toinertia. rlhis moves the block 19 upwardly and with it the arms 18`andcarriages 14. rlhis movement causes the carriages and cutters to bemoved away from one another as shown in Fig. 2. ln such position thecutters are expanded so as to en age lthe walls of the hole and rotationwi l underream a hole as desired.

When it is wished to pull the tool it isA CIB i the combination of abody adapted to be secured to a rotatable stem, carriages mounted uponthe sides of said body so `-as to be moved laterally with respect to thei axis thereof, cutters mounted on said'car riages, a control memberrotatably secured to said body, and linkage connecting said carriagesand said member whereby rotation of the latter will move said carriages.

2. In a rotary underreamer, the combination of a body adapted to besecured to a drill pipe, carriages mounted upon the sides of said bodyso as to be moved laterally with respect to the axis thereof, cuttersmounted on said carriages, a control member having a stem threadedlyengaged with said body whereby rotation of said control member will movesaid stem longitudinally of said body, and linkage connecting saidcarriages and said stem wherebyto move said carriage. p

3. A rotary underreamer, a combination of a body adapted to be securedto a drill pipe, said body being provided with ways at the sidesthereof, diverging from the axis, carriages mounted in said ways so thatmovement of said carriages in said ways will be both longitudinal andlateral to the axis of said body, a control member rotatably secured tosaid body, and linkage connecting said carriages and said member wherebyrotation of the latter will move said carriages.

4. In a rotary underreamer, the combination of a body adapted to besecured to a the axis, carriages mounted in said ways so that movementof said carriage in said ways will be both longitudinal and lateral,

' of said control member will move said stem longitudinally of saidbody, and linkage connecting said carriages and said member wherebyrotation of the latter will move said carriages.

5. In a rotary underreamer,'the combination of a body adapted to besecured to a drill pipe, saidbody being providedwith ways at the sidesthereof diverging from the axis, carriages mounted in said ways so thatmovement of said carriages in said ways will be both longitudinal andlateral, cutters mounted on said carriages, a control member having astern threadedly engaged with said body, whereby rotation of saidcontrol member will move said stem longitudinally of said body, armspivotally connecting said carriages and said stem yto provide a linkagewhereby rotation of said stem will move said carriage.

6. In a rotary underreamer, the combination of `a body adaptedv to'besecured to a drill pipe, said body being provided with ways at the sidesthereof diverging from the axis, carriages mounted in said ways so thatmovement of said carriages will be WILLIAM M'EnEDrri-I.

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